Although Sally Shelton-Colby is "an old friend of Leslie Manigat" {"A Chance for Democracy in Haiti," op-ed, Feb. 9}, she obviously does not know the man well enough. The vicissitudes of Haiti, especially during the past two years, have offered all Haitians, including the politicians, a chance to prove they are genuine democrats committed to a democratic political system based on -- and responsive to -- political participation.

While a few presidential candidates have passed that test, Mr. Manigat, among others, has failed it. One of the hottest questions in Haiti these days is not whether, but to what degree, Leslie Manigat was involved in the tragic events of Nov. 29, 1987, when the first free elections Haiti was going to have in more than 50 years were canceled.

Mr. Manigat "has created a dilemma for his friends in the United States" because his friends believe his words more than his deeds and, in their paternalistic attitude, keep seeing in one individual "a chance for democracy in Haiti" while the nation has voted for a constitution waiting to be respected and enforced.

In this regard, how Mr. Manigat arrived where he is will determine his course as the chief of state. Already he has started to express his gratitude by nominating Gen. Williams Regala as minister of defense in a provocative violation of Article 267 of the constitution. He has not started "by throwing out the thugs," as Sally Shelton-Colby suggested; the thugs are well in.

The time has come for SallyShelton-Colby, as well as the United States, to decide whether they are friends of the people of Haiti or of well-educated but ruthless politicians. This will be the single chance for democracy and peace in my country.

HENRY ROBERT DUBOIS Rockville